Explore The Universe @ Google Sky

Google Sky which was formerly available only within the Google Earth software, can now be checked with your browser as well. It lets you explore through the galaxy and check out different celestial bodies in ultraviolet, infrared, x-ray, or microwave light. The navigation is almost familiar to the well known Google Maps and the best part about it is you can search the galaxy by typing astronomy terms into the search box.

Three optical sky surveys that shows you what your naked eye would see if it had a really good zoom lens. Try switching to infrared, microwave, ultraviolet, or X-ray to see the sky in a completely different light or blend between these views to create unique visualizations on the fly.

Galleries highlighting the best images from Hubble and many other telescopes.

Current planet positions and constellations.

Overlays of custom KML content. (Simply paste a Sky KML URL into the search box, just like on Google Maps.)

The Earth & Sky podcasts gallery, which is a interesting feature worth checking.